#include <bits/stdc++.h>
using namespace std;

int main(){
	long long int n;
	cin >> n;
	long long int mod = 1000000007;
	vector<long long int> a(n+1);
	a[0] = 1; a[1] = 2; a[2] = 2;
	for(int i = 3; i < n; i++){
		a[i] = a[i-2] + a[i-3];
	}
	cout << a[n-1] % mod << endl;
	return 0;
}